Defaults

Current boundary:

• the def-based meta family (macros, alternatives, defaults, templates) is planned for a future release; none of it is part of the current compiler surface
• everything below describes intended design, not current behavior

Defaults are intended to change option defaults within an already legal capability tier. They cannot turn a heap-backed type into a core type or grant hosted APIs. In particular, str remains a memo type regardless of a future mutability/default declaration. A possible future spelling for changing its option defaults is:

def 'str': def[] = 'str[new,mut,nor]'